- try to process multiple presentations in parallel

...bluebutton/presentation/DocumentConversionServiceImp.java

.../bigbluebutton/presentation/imp/PageProcessorService.java

...ava/org/bigbluebutton/presentation/imp/PageToConvert.java

...org/bigbluebutton/presentation/imp/PdfPageDownscaler.java

...ton/presentation/imp/PdfToSwfSlidesGenerationService.java

...entation/imp/PresentationConversionCompletionService.java

...luebutton/presentation/imp/PresentationFileProcessor.java

...bigbluebutton/presentation/imp/PresentationToConvert.java

...rg/bigbluebutton/presentation/imp/SvgImageCreatorImp.java

...rg/bigbluebutton/presentation/imp/TextFileCreatorImp.java

...g/bigbluebutton/presentation/imp/ThumbnailCreatorImp.java

...presentation/messages/IPresentationCompletionMessage.java

...ton/presentation/messages/PageConvertProgressMessage.java

...ton/presentation/messages/PresentationConvertMessage.java

bigbluebutton-web/grails-app/conf/spring/doc-conversion.xml

bigbluebutton-web/grails-app/conf/spring/resources.xml